Using the Slots on a Supervisor Engine 2

The Supervisor Engine 2 has one Flash PC card (PCMCIA) slot.

With PCMCIA Advanced Technology Attachment (ATA) FlashDisk devices, the keyword for the slot on the active Supervisor Engine 2 is disk0: and the keyword for the slot on a redundant Supervisor Engine 2 is slavedisk0:.

With non-ATA Flash PC cards, the keyword for the slot on the active Supervisor Engine 2 is slot0: and the keyword for the slot on a redundant Supervisor Engine 2 is slaveslot0:.

Switch Fabric Module Overview

The Switch Fabric Module creates a dedicated connection between fabric-enabled modules and provides uninterrupted transmission of frames between these modules. In addition to the direct connection between fabric-enabled modules provided by the Switch Fabric Module, fabric-enabled modules also have a direct connection to the 32-Gbps forwarding bus.

The Switch Fabric Module does not have a console. A two-line LCD display on the front panel shows fabric utilization, software revision, and basic system information.

Switch Fabric Module Slots

With a 13-slot chassis, install the Switch Fabric Modules in either slot 7 or 8.

With all other chassis, install the Switch Fabric Modules in either slot 5 or 6.

Switch Fabric Redundancy

The Switch Fabric Module first installed functions as the primary module. For redundancy, you can install a redundant Switch Fabric Module. When two Switch Fabric Modules are installed at the same time, the module in the upper slot functions as the primary module, and the one in the lower slot functions as the backup. If you reset the module installed in the upper slot, the one in the lower slot becomes active.

No configuration is required for Switch Fabric Module redundancy. The module in the upper slot functions as the primary module and a redundant Switch Fabric Module in the lower slot automatically takes over if the primary module fails.

Forwarding Decisions for Layer 3-Switched Traffic

Either a PFC2 or a Distributed Feature Card (DFC) makes the forwarding decision for Layer 3-switched traffic as follows:

•A PFC2 makes all forwarding decisions for each packet that enter the router through a module without a DFC.

•A DFC makes all forwarding decisions for each packet that enters the router on a DFC-enabled module in these situations:

–If the egress port is on the same module as the ingress port, the DFC forwards the packet locally (the packet never leaves the module).

–If the egress port is on a different fabric-enabled module, the DFC sends the packet across the SFM to the egress module, which sends it out the egress port.

–If the egress port is on a different nonfabric-enabled module, the DFC sends the packet across the SFM to the Supervisor Engine 2. The Supervisor Engine 2 fabric interface transfers the packet to the 32-Gbps switching bus where it is received by the egress module and is sent out the egress port.

Switching Modes

When you install a Switch Fabric Module, the traffic is forwarded to and from modules in one of the following modes:

•Compact mode—The router uses this mode for all traffic when only fabric-enabled modules are installed. In this mode, a compact version of the DBus header is forwarded over the switch fabric channel, which provides the best possible performance.

•Truncated mode—The router uses this mode for traffic between fabric-enabled modules when there are both fabric-enabled and nonfabric-enabled modules installed. In this mode, the router sends a truncated version of the traffic (the first 64 bytes of the frame) over the switch fabric channel.

•Bus mode (also called flow-through mode)—The router uses this mode for traffic between nonfabric-enabled modules and for traffic between a nonfabric-enabled module and a fabric-enabled module. In this mode, all traffic passes between the local bus and the supervisor engine bus.

Table 6-1 shows the switching modes used with fabric-enabled and nonfabric-enabled modules installed.

Table 6-1 Switching Modes with Switch Fabric Module Installed

Modules

Switching Modes

Between fabric-enabled modules (when no nonfabric-enabled modules are installed)

Caution If you enter the
fabric required command on a router that does not have a Switch Fabric Module installed, all modules except the supervisor engine turn off.

When configuring fabric-required mode, note the following information:

•If you boot the router with fabric-required mode configured but without a Switch Fabric Module installed, only the supervisor engine receives power; no switching modules power up.

•When the router is operating with fabric-required mode configured and a Switch Fabric Module installed, if you remove the switch fabric module or if it fails, the router removes power from all switching modules; only the supervisor engine remains active.

•When the router is operating with fabric-required mode configured and with redundant Switch Fabric Modules installed, if you remove both switch fabric modules or if both fail, the router removes power from all switching modules; only the supervisor engine remains active.

Configuring an LCD Message

To configure a message for display on the LCD, perform this task:

Command

Purpose

Router(config)# fabric lcd-bannerd message d

Configures a message for display on the LCD.

Router(config)# no fabric lcd-banner

Clears the message displayed on the LCD.

When configuring a message for display on the LCD, note the following information:

•The d parameter is a delimiting character. You cannot use the delimiting character in the message. The delimiter is a character of your choice—a pound sign (#), for example.

•You can use the following tokens, in the form $(token), in the message text:

–$(hostname)—Displays the router's host name.

–$(domain)—Displays the router's domain name.

Monitoring the Switch Fabric Module

The Switch Fabric Module supports a number of show commands for monitoring purposes. A fully automated startup sequence brings the module online and runs the connectivity diagnostics on the ports.